Sink



FIG. 1 is a perspective view taken from the top, front and left side of a sink showing new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof; and

FIG. 5 is a front elevational view thereof, the rear being a mirror image of the front. 

The ornamental design for a sink, as shown and described. 